Rabies is an encephalitis, or brain disease, which is caused by the rabies virus.
It is a fatal condition caused after being bitten by an infected animal, usually a rabid dog or a bat.
There is a vaccination against the disease, but once symptoms of rabies have developed the condition is almost always fatal - and the few people who have survived have suffered serious long-term disabilities.
Most countries of the world have rabies and there are only a few, including Britain, the Antarctic and Australia, which have been declared rabies free.
But anyone bitten by a bat in the UK should still seek medical advice.
The last case of rabies in the UK was in November 2002, when a conservation worker was bitten by a rabid bat.
But there have been no cases in the UK of rabies being transmitted by a dog over the last 100 years.
Travelling in developing countries is the most risky, particularly the more remote areas, as clinics do not always have supplies of the vaccine. The vaccine can be successful after a person has been bitten, if it is taken early enough.
Rabies affects the central nervous system.
Initial symptoms can include anxiety, headaches and fever. As the condition progresses the patient will have spasms of their swallowing muscles, a fear of water and respiratory failure will set in.
Travellers going to countries where rabies is endemic are advised to have the rabies vaccine. This is a safe and effective jab and should be considered by anyone who is bitten or scratched by a warm blooded animal in a country with rabies.
Travellers abroad are advised to steer clear of animals, particularly stray or unattended dogs.